Oh yeah, it isn’t entirely easy. I teach classes at work on OAuth2 with the web services that we use and I totally understand the glazed looks of folks on webcams.
If anything, do not worry at first about getting an authorization token and viewing protected data. With just the Client-ID you are able to query quite a bit of data to get your hands dirty (so to speak). Once you have the methodologies figured out for querying and parsing data then worry about moving further along with OAuth into access tokens, if you even need to for your class.
You can do some basic tests from the command line if you install a tool such as Curl (https://curl.haxx.se/download.html) even. This may be good if you just want to play around and see what is coming back in queries. Twitch provides example of using Curl in their API documentation as well each step of the way.
Cheers